1. Field of the Invention
This invention relates to a lock structure for locking or holding a condition in which male and female connector housings mutually fit together.
2. Description of the Related Art
FIG. 13 shows a connector 1 (disclosed in Japanese Utility Model Unexamined Publication No. 56-7287) using a lock device. In this Figure, this connector 1 comprises a male connector housing 2, and a female connector housing 4 having a hood portion 3 into which the male connector housing 2 is inserted and fitted. The male connector housing 2 has an elastic lock arm 6 supported thereon in a cantilever manner on a fitting side 5 of the housing. A lock projection 7 is formed on the lock arm 6 at an intermediate portion thereof, and an operating portion 8 is provided at a free end of the lock arm 6.
A groove 9 for receiving the lock arm 6 is formed in the hood portion 3 of the female connector housing 4, and a retaining member 10, extending between opposite sides of the groove 9, is provided on the hood portion 3. When the male and female connector housings 2 and 4 are fitted together, the lock arm 6 is inserted into the groove 9, and the lock projection 7 engages with the retaining member 10.
In this case, when the male connector housing 2 is inserted into the hood portion 3, the lock projection 7 abuts against the retaining member 10. When the male connector housing 2 is further inserted deep into the hood portion 3, the lock arm 6 is flexed (i.e., elastically deformed) to allow the lock projection 7 to pass the retaining member 10. The lock arm 6 is thereafter restored to its initial position because of its own elasticity, so that the lock projection 7 engages with the retaining member 10. When the lock projection 7 is thus engaged with the retaining member 10, there is achieved a locked condition in which the male and female connector housings 2 and 4 are held in a mutually fitted condition.
However, connectors such as the one shown in FIG. 13 suffer from drawbacks. If the lock arm 6 is kept flexed under the influence of an external force, the lock projection 7 on the lock arm 6 will fail to properly engage with the retaining member 10 when the male connector housing 2 is inserted into the hood portion 3. There may be a sensation of incongruous operation, as compared with an ordinary operation. Additionally, the lock projection 7 will not properly engage with the retaining member 10, even after the lock projection 7 passes the retaining member 10.